This invention relates generally to a method and device to update the data transfer count for a disc drive while data is being transferred.
Computers are frequently connected to an optical disc drive. Data is transferred to and from the optical drive which has a large storage capacity. Data transfers to and from optical disc drives tend to be a good deal slower than transfers from memory chips or magnetic storage mediums. One of the reasons data transfer is slow is the inability to add additional data to a data transfer once the transfer has been initiated. In a conventional write operation, data is written to the disc in blocks, and each block has a predetermined number of bytes. The number of blocks to be written is determined before the write operation is started. This number is set in a counter. As each successive block is written the intermediate count value held by the counter is decremented. When the intermediate count value reaches zero the write operation is complete. Under such an arrangement, the number of blocks to be written to the disc in a given write sequence is specified prior to beginning the data transfer and the number of blocks to be written on the disc cannot be changed during the write sequence. Instead, to transfer additional blocks, a separate write sequence must be initiated. Initiating a separate write sequence is cumbersome and increases the amount of time to transfer data to the disc.
In view of the foregoing, it would be highly desirable to provide a method and device that allows the number of blocks to be written to a disc to be changed during a data transfer operation. Such a method and device would reduce the amount of time to write data on an optical disc.
A device modifies an amount of data transferred during a data transfer operation with a disc drive. A data counter generates an intermediate count value in accordance with an amount of data to be transferred. An augmenter augments the intermediate count value by a specified count value to generate an updated count value. The updated-count value is loaded into the data counter such that the intermediate count value becomes equal to the updated count value during the data transfer operation.
In another aspect of the invention, a disc controller uses the device to write data on the disc. Yet another aspect of the invention provides a method of modifying the amount of data transferred during a data transfer operation with a disc drive.
By modifying the amount of data during a data transfer operation, the invention reduces the amount of time to record data on the optical disc.